It is known to form a combination type heat exchanger wherein a common fluid is placed in heat exchange relationship with a pair of heat exchanger cores, each including a plurality of spaced apart heat exchanging tubes. In some instances, a single common inlet manifold tank and a single common outlet manifold tank are in fluid communication with each of the heat exchanger cores, while further including a baffle or other separating means within each of the manifold tanks to separate a first fluid associated with the first heat exchanger core from a second fluid associated with the second heat exchanger core. Such an arrangement advantageously allows for the common fluid to pass between the heat exchanging tubes of each respective heat exchanger core while exchanging heat with each of the first fluid and the second fluid simultaneously. A packaging size of the combination heat exchanger is thus minimized.
However, one issue associated with the use of a combination type heat exchanger arises when the first fluid and the second fluid have different temperatures, thereby causing each chamber formed in one of the common manifold tanks to be exposed to a different temperature than an adjacent chamber therein. This difference in temperature leads to varying degrees of thermal expansion occurring in each of the separated chambers. These varying degrees of thermal expansion can lead to failure when a portion of one of the manifold tanks expands or contracts relative to an adjacent portion of the same manifold tank, thereby causing a localized deformation of the manifold tank that can lead to failure thereof.
Accordingly, one solution to the problem of thermal expansion within the combination type heat exchanger is a complete or partial separation of each chamber of each of the manifold tanks into a separate manifold tank associated with only one of the respective heat exchanger cores. Each of the separate manifold tanks must then be coupled together to maintain a desired relationship therebetween. Such combination heat exchangers utilize mechanical attachment structures for coupling the separate manifold tanks, but the mechanical attachment structures add unnecessary weight, require additional and complicated manufacturing steps, and can lead to additional failure mechanisms between the coupled manifold tanks.
It is therefore desirable to provide a combination heat exchanger having a coupling with a thermal expansion accommodating feature to accommodate a thermal expansion between a pair of adjacent heat exchanger cores of the combination heat exchanger, wherein the coupling has a simplified structure that promotes an ease of manufacturing of the combination heat exchanger.